Low ignition propensity wrapping paper for cigarettes has become known in recent years. This wrapping paper has applications of a combustion inhibition agent in predetermined regions.
Specifically, low ignition propensity wrapping papers disclosed in patent documents 1 and 2 comprise a web of paper and combustion inhibition bands on the web spaced from one another by a predetermined distance along the length of the web. The combustion inhibition bands are formed by applying a solution of a combustion inhibition agent to the web. The web with the combustion inhibition agent solution applied is then dried with a dryer, so that low ignition propensity wrapping paper is completed.
In recent years, in countries including the USA, regulations concerning low ignition propensity cigarettes have come into effect. In the USA, for example, cigarettes are required to meet the standard for full-length burn ratio (FLB ratio), where the full-length burn ratio is measured and calculated in accordance with the ASTM (American Society for Testing and Materials) standard E2187-04. Cigarettes meeting the FLB ratio standard (low ignition propensity cigarettes) include a paper wrapper with bands formed by applying a combustion inhibition agent, spaced from one another along the axis of the cigarette.
In forming such combustion inhibition bands, or in other words, applying a combustion inhibition agent solution to the web, a gravure roll is used as disclosed in patent documents 1 and 2. The gravure roll has transfer regions on an outer circumferential surface thereof, corresponding to to-be-formed combustion inhibition bands. The transfer regions are equally spaced from one another along the circumference of the gravure roll.
Specifically, the transfer regions each include a large number of recesses called cells, the cells being uniformly distributed in each transfer region. The cells in each transfer region hold a combustion inhibition agent solution. Combustion inhibition bands are formed on the web by transfer of the combustion inhibition agent solution from the cells to the web.